1. Field of the Invention
The invention relates to an automatic device for the micro-sampling and injection of a pressurized fluid with a view to an analysis, for example by chromotography, after transfer of the fluid sample into the flow of a carrier liquid or gas.
2. Description of the Prior Art
Taking samples of a fluid under high pressure is an extremely delicate procedure and the methods currently used for such sample taking have numerous drawbacks which have been indicated in the patent No. FR-A-2 476 311 of the applicant. This patent describes a device for taking samples of a pressurized gas or liquid product comprising a first duct through which the product to be sampled passes, a second duct through which the carrier gas or liquid passes, a conduit communicating between these two ducts and a member controllable for normally closing and temporarily opening the communication passage, such opening only taking place during the sample taking period. Such a device avoids the drawbacks associated with the prior known methods and it further provides a method for the automatic control of the manufacturing procedures in a loop. It provides for sampling at the output of a reactor analysis of the samples, and controlling the reactor operation to optimize results.
Such a known device has proved to be an extremely precious tool in so far as the sample taken alone is concerned. However, with such a device, the samples taken must be conveyed by a carrier, which is difficult or even impossible in gas chromotography if the sample taken is a liquid formed of compounds with high boiling points and if the carrier is a gas with a temperature substantially less than the boiling point of one or more of the compounds of the mixture,(slow or imperfect vaporization in the circuit of a gas chromatograph, used as apparatus for analyzing the sample, leads to inaccurate or false analysis).
An aim of the present invention is to provide a device of the above mentioned type for injecting and vaporizing a liquid in an analysis circuit.